Initial Move from Azure DevOps to GitHub

src/Common/EditableUtility.ts

@@ -0,0 +1,94 @@
+import * as ko from "knockout";
+import * as ViewModels from "../Contracts/ViewModels";
+
+export default class EditableUtility {
+  public static observable<T>(initialValue?: T): ViewModels.Editable<T> {
+    var observable: ViewModels.Editable<T> = <ViewModels.Editable<T>>ko.observable<T>(initialValue);
+
+    observable.edits = ko.observableArray<T>([initialValue]);
+    observable.validations = ko.observableArray<(value: T) => boolean>([]);
+
+    observable.setBaseline = (baseline: T) => {
+      observable(baseline);
+      observable.edits([baseline]);
+    };
+
+    observable.getEditableCurrentValue = ko.computed<T>(() => {
+      const edits = (observable.edits && observable.edits()) || [];
+      if (edits.length === 0) {
+        return undefined;
+      }
+
+      return edits[edits.length - 1];
+    });
+
+    observable.getEditableOriginalValue = ko.computed<T>(() => {
+      const edits = (observable.edits && observable.edits()) || [];
+      if (edits.length === 0) {
+        return undefined;
+      }
+
+      return edits[0];
+    });
+
+    observable.editableIsDirty = ko.computed<boolean>(() => {
+      const edits = (observable.edits && observable.edits()) || [];
+      if (edits.length <= 1) {
+        return false;
+      }
+
+      let current: any = observable.getEditableCurrentValue();
+      let original: any = observable.getEditableOriginalValue();
+
+      switch (typeof current) {
+        case "string":
+        case "undefined":
+        case "number":
+        case "boolean":
+          current = current && current.toString();
+          break;
+
+        default:
+          current = JSON.stringify(current);
+          break;
+      }
+
+      switch (typeof original) {
+        case "string":
+        case "undefined":
+        case "number":
+        case "boolean":
+          original = original && original.toString();
+          break;
+
+        default:
+          original = JSON.stringify(original);
+          break;
+      }
+
+      if (current !== original) {
+        return true;
+      }
+
+      return false;
+    });
+
+    observable.subscribe(edit => {
+      var edits = observable.edits && observable.edits();
+      if (!edits) {
+        return;
+      }
+      edits.push(edit);
+      observable.edits(edits);
+    });
+
+    observable.editableIsValid = ko.observable<boolean>(true);
+    observable.subscribe(value => {
+      const validations: ((value: T) => boolean)[] = (observable.validations && observable.validations()) || [];
+      const isValid = validations.every(validate => validate(value));
+      observable.editableIsValid(isValid);
+    });
+
+    return observable;
+  }
+}